A connector capable of sufficiently shielding two connectors for connecting two circuit boards, and further making the connectors compact in size. A receptacle-side fitting portion (32) for being fitted to a plug-side fitting portion (142) of a plug connector (12) is formed in a receptacle-side housing (3) disposed on a printed circuit board (21). A plurality of receptacle-side contacts (5) are arranged in the receptacle-side fitting portion (32). A shell body (71) disposed around the receptacle-side fitting portion (32) is provided in a shell (7) mounted in receptacle-side housing (3). The shell (7) is formed with shell contact portions (72) brought into contact with plug-side ground contacts (16G) of the plug connector (12), and a shell terminal portion (73) fixed to a ground pad (21) of the printed circuit board (21).